JP2004510907A - Device for operating valve and method of controlling the device - Google Patents

Abstract

The invention comprises at least one drive (20), formed in the form of a jack, which is hydraulically controlled and drives the connected valve (12), inside the jack being connected to the valve. Movable piston (24) defines two opposing hydraulic chambers (28, 30), each supplied with an incompressible fluid (FHI), the hydraulic chambers (28, 30) being valves The control unit causes the pressure prevailing in one of the hydraulic chambers (28, 30) to alternately increase or decrease the pressure prevailing in the other hydraulic chambers to drive (12). Controlled, each hydraulic chamber (28, 30) is connected to a corresponding liquid pressure source (32, 34) for actuation, the liquid pressure source (32, 34) resiliently returning the fluid (FHI). Characterized by having means Provides an apparatus for operation of the valve of the heat engine of a motor vehicle (12) (10). The present invention also provides a method for controlling such a device (10).

Description

[0001]
The present invention relates to a valve operating device for a heat engine of a motor vehicle.
[0002]
The present invention is, in particular, a device for operating a valve of a heat engine of a motor vehicle,
Each valve has a shaft or stem,
The handle is coupled to a drive controlled by a control unit to cause the attached valve to separate from and return to the valve seat;
Each drive is made in the form of a jack with a cylinder,
Inside the cylinder, the stem of the mounted valve is slidable in the axial direction in a sealed state,
A movable piston connected to the free end of the stem of the valve is arranged inside the cylinder,
The piston defines two hydraulic chambers in the cylinder, opposing upper and lower hydraulic chambers, each supplied with an incompressible fluid;
In each hydraulic chamber, the pressure of the fluid is set alternately,
This pressure is such that the pressure dominating one of the hydraulic chambers is alternately high or low relative to the pressure dominating the other hydraulic chambers, in order to operate the jacks and valves alternately. Controlled by the control unit,
The present invention relates to a device for operating a valve of a heat engine of an automobile.
[0003]
Numerous examples of so-called "camless" actuators are known.
[0004]
These devices replace conventional mechanical devices having at least one camshaft driven by, for example, a crankshaft to move the valve stem directly or indirectly, for separating the valve from the valve seat. It is for.
[0005]
A well-known advantage of such a device is to apply various rules for optimally controlling the separation of the valve from the valve seat, which is determined by the control unit as a function of the engine speed in order to optimize the operation of the engine. Is that it becomes possible.
[0006]
As is well known, actuators of the "camless" type have drives of the electromagnetic or hydraulic type.
[0007]
Electromagnetic drives generally have two springs and a metal paddle that moves between two coils. When the valve is closed, the upper spring is compressed and supported by a paddle that is attracted toward the upper coil excited by the current. The lower coil is not energized and the lower spring is at rest. When the current circulation in the upper coil is interrupted, the paddle is opened, compressing the lower spring and causing the valve to open.
[0008]
This actuator is therefore called "oscillating", since the potential energy of the upper spring is transmitted to the paddle in the form of kinetic energy and then to the lower spring in the form of potential energy.
[0009]
Upon establishing current circulation in the lower coil, the valve is held open. Interrupting the current in the lower coil results in valve closure and recompression of the upper spring.
[0010]
Actuating devices having these electromagnetic drives have the problem of requiring high electrical output in order to guarantee operation. For example, for a four-cylinder, 16-valve engine, the power consumed solely by the operation of the "camless" engine can reach 2 kW at the highest engine speeds, but this power is equivalent to that of conventional automotive electrical accessories. This is the value consumed to perform all operations. For this reason, the power supply voltage of the electric circuit of the automobile is 12 V in the conventional case, but must be increased to 42 V in order to reduce the size of the generator.
[0011]
Furthermore, it has been shown that electromagnetic actuators are not suitable for engines operating at high speeds. Indeed, for such engines, electromagnetic actuators cannot sufficiently accelerate components that are moving beyond the normal speed of production engines.
[0012]
The document US-A-5.562.070 describes a hydraulic system capable of discharging high-pressure oil to two opposing hydraulic chambers of a jack forming a drive so as to cause reciprocation of the drive and the valve. A hydraulic actuator having a pump is described and shown. In such a device, the subsequent opposing movement of the jack is effected by alternately applying a higher pressure on each of the opposing faces of the piston of the drive than on the other face of the piston. can get. For this reason, such a hydraulic actuator consumes a large amount of hydraulic energy, especially when the engine speed is increased and the opening and closing speed of the valve is high. Thus, such devices provide little benefit compared to conventional timing driven devices.
[0013]
Furthermore, this device does not allow effective control of the valve speed at the end of the closing stroke, or at least does not allow control of the valve speed in proportion to the additional consumption of hydraulic energy. Therefore, such a device presents a problem that the valve seat may be damaged, a noise may be generated when the valve is closed on the valve seat at a very high speed, and a problem that the output of the engine is greatly reduced. .
[0014]
Document U.S. Pat. No. 5,572,961 describes a similar device in which the repetitive movement of the valve is performed by a spring. Such a device is of the "vibrating" type described above and makes it possible to greatly reduce the consumption of hydraulic energy required for the actuation of the valve. However, this device shows that the engine does not adapt to high engine speeds, especially the number of revolutions referred to as "valve surging", which can cause the springs to resonate and cause uncontrollable oscillations of large amplitude. .
[0015]
In order to solve these problems, the present invention provides a hydraulic and vibrating device in the form of a circulating hydropneumatic (combined with hydraulic) "camless" actuator. .
[0016]
For this purpose, the invention relates to a device of the type described at the beginning of the description, wherein each of the hydraulic chambers of the jack is connected to at least one independent hydraulic pressure source called an actuation source. And the liquid pressure source is connected to only one of the hydraulic chambers, the liquid pressure source being in opposition to the predetermined orientation during the course of movement of the valve in the predetermined orientation. An apparatus is provided, comprising means for resiliently returning the fluid to recover the kinetic energy of the valve for movement of the valve after orientation.
[0017]
According to a preferred embodiment of the present invention, the means for returning the fluid is pneumatic.
[0018]
According to another embodiment of the invention, these returns are mechanical.
[0019]
According to another feature of the invention,
At least one of the hydraulic chambers can be connected to an additional source, referred to as a drain source, at which the hydraulic pressure of the fluid is reduced;
The control unit includes: a driving solenoid valve provided between one of the hydraulic chambers and the operating source coupled to the one of the hydraulic chambers; and one of the hydraulic chambers and the discharge source. It is possible to adjust the pressure governing the hydraulic chamber of the jack by alternately controlling the discharge solenoid valve provided between
Each of the actuation sources is comprised of a liquid-gas accumulator, wherein the liquid-gas accumulator has a coating, in which the membrane separates a restoration chamber and an activation chamber, and the restoration chamber is separated. The working chamber is connected to the corresponding upper or lower hydraulic chamber of the attached jack and is filled with the incompressible fluid. Yes,
The emission source has a storage tank connected to a crankcase of the engine where the reduced pressure governs.
The hydraulic chamber above the jack can be connected to a first liquid-gas accumulator or the discharge source via the driving solenoid valve and the discharge solenoid valve, respectively. The hydraulic chamber below the jack can be directly connected to a second liquid-gas accumulator;
A check valve is provided between the hydraulic chamber above the jack and the first liquid-gas accumulator;
Each of the working chambers of the liquid-gas accumulator is connected to a pressure maintaining device capable of maintaining a set pressure as long as the valve is closed.
[0020]
The invention also provides a method of controlling a device of the type described above,
In a first stroke, referred to as closing the valve, the control unit commands the closing of the drive solenoid valve and the opening of the discharge solenoid valve, and the first liquid-gas accumulator is The pressure maintaining device is maintained at a first set pressure, the second liquid-gas accumulator is maintained at a second set pressure, the first set pressure is higher than the second set pressure, and The set pressure of 2 is higher than the reduced pressure of the crankcase of the engine,
Next, in a second stroke called separation of the valve from the valve seat, the control unit commands the closing of the discharge electromagnetic valve and the opening of the drive electromagnetic valve,
Next, in a third stroke called return of the valve to the valve seat, the control unit commands the closing of the electromagnetic valve for driving,
Then, in a fourth stroke in which the valve is completely closed, the control unit commands the opening of the discharge solenoid valve until the first stroke in which the valve is closed.
A method for controlling an apparatus is provided.
[0021]
Other features and advantages of the present invention will become apparent from the following detailed description, which refers to the accompanying drawings for an understanding.
[0022]
FIG. 1 is a schematic view of the device according to the invention in the closed position of the valve.
[0023]
FIG. 2 is a schematic view of the device according to the invention in the position of the valve away from the valve seat.
[0024]
FIG. 3 is a schematic view of the device according to the invention in the return position of the valve to the valve seat.
[0025]
In the following description, the same reference numerals indicate parts having the same or similar functions.
[0026]
FIG. 1 shows an entire actuating device 10 for a valve 12 of a motor vehicle heat engine made in accordance with the present invention.
[0027]
In the actuator 10, each valve 12 is formed from a tulip-shaped member 14 and a shaft or handle 16 connected to the tulip-shaped member 14. The handle 16 is coupled to a drive 18, for example controlled by an electronic control unit (not shown), to cause the valve 12 to separate from and return to the valve seat (not shown). Have been.
[0028]
The drive 18 is, as is well known, made in the form of a jack 20 having a cylinder 22 in which the handle 16 of the associated valve 12 is axially slidable in a sealed manner, A movable piston 24 connected to the free end of the stem 16 of the valve 12 is arranged. The piston 24 defines two opposing hydraulic chambers in the cylinder 22 which are supplied with an incompressible fluid FHI, for example oil. Thus, piston 24 defines, in cylinder 22, an upper hydraulic chamber 28 and a lower hydraulic chamber 30, more particularly.
[0029]
During operation of the actuator 10, one of the hydraulic chambers 28 or 30 is used to alternately operate the jack 20 and the valve 12 in each of the upper hydraulic chamber 28 and the lower hydraulic chamber 30. The pressure of the incompressible fluid FHI controlled by the control unit is set such that the pressure dominating the pressure alternately becomes higher or lower than the pressure controlling the other hydraulic chambers.
[0030]
In this way, when the pressure P ₂₈ dominating in the hydraulic chamber ₂₈ is higher than the pressure P ₃₀ dominating in the hydraulic chamber 30, the resultant of the pressures acting on the opposing surfaces of the piston 24 is: The piston 24 is pushed downward in the direction of the opening of the valve 12. Conversely, when the pressure P ₃₀ dominating in the hydraulic chamber 30 is higher than the pressure P ₂₈ dominating in the hydraulic chamber 28, the resultant of the pressures acting on the opposing surfaces of the piston 24 is Pushes the piston 24 upward in the direction of closure.
[0031]
According to the present invention, each of the hydraulic chambers 28 or 30 of the jack 22 may be connected to at least one independent hydraulic pressure source, referred to as an actuation source, to solve the above-described problems of the prior art devices. It is possible. The actuation source is coupled to one of the hydraulic chambers 28 or 30 and has pneumatic means for resiliently returning the incompressible fluid FHI. The pneumatic means is for recovering the kinetic energy of the valve 12 during a subsequent movement of the valve 12 during a movement of the valve 12 in a predetermined orientation.
[0032]
Thus, the actuation device 10 according to the invention preferably has two actuation sources 32 and 34. This arrangement is not a limitation of the present invention and may have one or more actuation sources coupled to each of the hydraulic chambers 28 or 30 of the jack 22.
[0033]
This configuration offers a number of advantages over prior art devices.
[0034]
Indeed, as is well known, conventional devices for actuating a valve by a camshaft have the disadvantage that the law of optimally controlling the separation of the valve from the valve seat cannot be applied; It is possible to effectively control the closing speed. Providing a curved, raised profile in the area of the cam suitable for controlling the closure of the valve can provide a reduced velocity to the valve approaching the valve seat, which results in wear of the valve seat Risk and increase the life of the device.
[0035]
To date, most "cam-less" devices have exhibited the problem of sudden opening and closing of the valve, which after a certain time causes significant wear on the valve seat, More often results in noise.
[0036]
The device according to the invention solves this problem because the valve 12 is moved at a substantially zero speed, which can be controlled by a decrease in hydraulic pressure upstream of the solenoid valve EVD, when approaching the limit position of operation. To be able to This reduction in hydraulic pressure can be a function of valve position.
[0037]
To provide the opening of the valve 12 according to the present invention, the first actuation source transfers all of its potential energy to the valve 12 in the form of kinetic energy. This kinetic energy is transferred to the second actuation source, this time in the form of potential energy, when the valve 12 reaches full opening at the end of the stroke. Conversely, to effect closure of the valve 12, the second actuation source transfers all of its potential energy to the valve 12 in the form of kinetic energy. This kinetic energy is transferred to the first actuation source, this time in the form of potential energy, when the valve 12 reaches closing at the end of the stroke. The kinetic energy of the valve 12 is almost zero when closed, whereas the kinetic energy is proportional to the square of the velocity, so the velocity of the valve 12 is also almost zero.
[0038]
Another advantage of the device 10 according to the invention is that it consumes little energy of the liquid.
[0039]
Since energy is stored in the actuation sources 32 and 34 of pressure, there is no need to provide additional liquid pressure to reverse the movement of the valve 12, as in prior art devices. Thus, the consumption of liquid pressure is summarized in the minimum supply of liquid energy described below to compensate for the loss of kinetic energy of the valve 12 during movement. The loss of kinetic energy is particularly caused by various frictions that may be interposed in the drive 18.
[0040]
On the other hand, according to the invention, at least one of the hydraulic chambers 28 or 30 can be connected to an additional discharge source 36. In the source 36, the incompressible fluid FHI is depressurized.
[0041]
In this way, the hydraulic pressure in one of the hydraulic chambers is advantageously reduced to a reduced pressure in order to ensure stability at the end position of the valve 12 in relation to the setting of the reduced pressure in the hydraulic chamber. It is possible to return.
[0042]
According to the invention, the adjustment of the pressures P ₂₈ , P ₃₀ acting on each of the opposing faces of the piston 24 in order to cause an upward or downward movement of the piston 24 is managed entirely by the control unit.
[0043]
Thus, as a whole, the control unit comprises a solenoid valve EVA provided between one of the hydraulic chambers 28 or 30 of the jack 20 and its associated actuation source 32 or 34, and one of the hydraulic chambers 28 or 30 The pressures P ₂₈ , P ₃₀ governing the hydraulic chambers 28 and 30 of the jack 20 can be adjusted by alternately controlling the solenoid valve EVD provided between the pressure source and the discharge source 36. It is.
[0044]
In a preferred embodiment of the invention, each actuation source 32 or 34 comprises a liquid-gas accumulator 32 or 34. The liquid-gas accumulator 32 or 34 has a coating 38, 40 in which the membranes 42, 44 delimit the recovery chambers 46, 48 and the working chambers 50, 52. The recovery chambers 46, 48 are isolated and filled with a compressible gas GC, and the working chambers 50, 52 are connected to the corresponding upper hydraulic chamber 28 or lower hydraulic chamber 30 of the attached jack 20. , Filled with an incompressible fluid FHI.
[0045]
The compressible gas GC contained in the recovery chambers 46 and 48 of the liquid-gas accumulators 32 and 34 makes it possible to exert an elastic restoring action on the incompressible fluid FHI contained in the working chambers 50 and 52. Thus, it constitutes a gas spring which allows the kinetic energy of the valve 12 to be stored. The operating device 10 operates without exhibiting a defect as an electromechanical driven vibration device, that is, without exhibiting a defect due to a large inertia.
[0046]
In addition, the exhaust source 36 has a storage tank 54 connected to a crankcase (not shown) of the engine where the reduced pressure “P _r ” governs.
[0047]
The discharge source 36 as specified so far can be coupled to either the hydraulic chamber 28 above the jack 20 or the hydraulic chamber 30 below without changing the operating principle of the actuator 10. It should be noted.
[0048]
However, the closed position of the valve 12, i.e. the position at which the pressure of one of the hydraulic chambers of the jack 20 is reduced, corresponds to the closed position of the valve 12, which ensures a perfect fit of the tulip-shaped member 14 onto the valve seat. It is desirable to do.
[0049]
Therefore, the hydraulic chamber 28 above the jack 20 can be connected to the first liquid-gas accumulator 32 and the discharge source 36 via the solenoid valve EVA and the solenoid valve EVD, respectively. The pressure chamber 30 is directly connected to the second liquid-gas accumulator 34.
[0050]
Further, a check valve 56 can be disposed between the hydraulic chamber 28 above the jack 20 and the first liquid-gas accumulator 32.
[0051]
Finally, each working chamber 50 or 52 of the liquid-gas accumulator 32 or 34 is provided with a pressure maintenance device () capable of maintaining that working chamber at the set pressures Pc ₃₂ and Pc ₃₄ as long as the valve 12 is closed. (Not shown).
[0052]
This pressure maintenance device makes it possible in particular to compensate for the loss of hydraulic energy incurred by the fluid during the movement of the valve 12. These hydraulic energy losses are caused by the friction of the shaft of the valve 12 in the cylinder 22, the friction of the piston 24 in the cylinder, and the "fluid friction" type created by the pressure acting in the incompressible fluid FHI. In particular due to the loss of
[0053]
The present invention also provides a control method for ensuring the operation of the above-described actuator 10 in this configuration.
[0054]
In a first stroke, shown in FIG. 1, called closing of the valve 12, the control unit commands the closing of the driving solenoid valve EVA and the opening of the discharging solenoid valve EVD. The first liquid-gas accumulator 32 is maintained at a first set pressure Pc ₃₂ by a pressure maintaining device, and the second liquid-gas accumulator 34 is maintained at a second set pressure Pc ₃₄ . The first set pressure _{Pc 32} is higher than the second set pressure _{Pc 34,} the second set pressure _{Pc 34} is higher than the vacuum pressure in the crankcase _{"P r"} of the engine.
[0055]
Thus, the pressure P ₂₈ dominating in the hydraulic chamber 28 above the jack 20 is equal to the depressurized pressure “P _r ” of the crankcase, and thus the set pressure dominating in the hydraulic chamber below the jack. Being lower than Pc ₃₄ , valve 12 rests and closes. Since the working chamber 50 of the liquid-gas accumulator 32 is ready to set the set pressure Pc ₃₂ into the hydraulic chamber 28 above the jack, irrespective of the opening of the solenoid valve EVA, the operating device is "filled". Called "in state."
[0056]
In a second stroke, called the separation of the valve 12 from the valve seat, the control unit commands the closing of the discharge solenoid valve EVD and the opening of the drive solenoid valve EVA. The pressure P ₂₈ is equal to the set pressure Pc ₃₂ governing the inside of the upper hydraulic chamber 28 is higher than the set pressure Pc ₃₄ governing the inside of the hydraulic chamber 30 beneath the jack, the pressure acting on the piston 24 Produces a downward displacement on the piston 24 in the direction in which the valve 12 opens.
[0057]
As the valve 12 opens, the displacement of the valve 12 causes an increase in the volume of the upper hydraulic chamber 28 and thus the expansion of the compressible gas GC contained in the recovery chamber 46 of the liquid-gas accumulator 32, and Of the hydraulic chamber 30 and thus the compression of the compressible gas GC contained in the recovery chamber 48 of the liquid-gas accumulator 34.
[0058]
The acceleration of the valve 12 decreases until the pressure prevailing in the two recovery chambers 46, 48 is equalized to zero. This position of the valve 12 corresponds to the maximum kinetic energy stored by the valve 12, and thus the highest speed. Next, the displacement of the valve 12 continues, and the deceleration of the valve 12 continues until the valve 12 reaches the fully open position at zero speed.
[0059]
At this moment, the kinetic energy of the valve 12 is substantially entirely converted to potential energy stored in the gas spring constituted by the compressible gas GC contained in the recovery chamber 48 of the liquid-gas accumulator 34. . Thus, the pressure in the recovery chamber 48 is close to the pressure prevailing in the recovery chamber 46 at the beginning of the second stroke, except for the pressure drop.
[0060]
Thus, the incompressible fluid FHI is now at approximately the first set pressure Pc ₃₂ in the hydraulic chamber 30 below the jack and approximately at the second set pressure Pc ₃₂ in the hydraulic chamber 30 above the jack. a set pressure _{Pc 34.} At that time, the control unit commands the closing of the solenoid valve EVA.
[0061]
The resultant value of the pressures P ₂₈ , P ₃₀ acting on the piston 24 is then reversed and in a third stroke, called return of the valve to the valve seat, the control unit commands the closing of the drive solenoid valve EVA. .
[0062]
At that time, the valve 12 begins its closing movement as soon as the increase in the pressure P _{28 in} the upper hydraulic chamber 28 is sufficient. If the device has a check valve 56, the setting of the threshold value of the check valve 56 allows the determination of the dwell time of the separation of the valve from the valve seat when the valve is fully open, If there are slight defects, this can be returned to a possibly negligible value.
[0063]
The characteristics of the closing movement of the valve 12 are exactly analogous to the opening movement. It is therefore noted that the valve 12 closes on its seat with virtually zero speed, and thus does not result in wear of the valve seat, which significantly increases the life of the engine under consideration. Should.
[0064]
Finally, in a fourth stroke, which is a complete closure of the valve 12 which occurs when the valve 12 is newly closed, to reduce the pressure P ₂₈ remaining in the hydraulic chamber 28 above the jack. , The control unit commands the opening of the solenoid valve EVD. The actuator 10 is then brought back to the configuration of the first stroke of closing the valve 12 as soon as the pressure has stabilized.
[0065]
If the actuator 10 has a check valve, it will be noted that the valve 12 will automatically close at the end of the period defined in relation to the threshold value of the check valve activation.
[0066]
It should be noted that as a possible variant, between the second and third strokes, this period can be controlled, i.e. the check valve 56 can be stopped and the time during which the valve 12 is in the open position can be fixed. is there. This form corresponds to a well-known exhaust gas recirculation method called EGR (Exhaust Gas Recycling), for example, when the actuator is applied to the exhaust valve 12, and the stroke to the bottom dead center of the piston. During this time, it is possible to keep the valve 12 open in order to facilitate performing a re-intake of the combustion gas.
[0067]
This configuration is particularly applicable to mass-produced automotive engines where minimal fuel consumption is required.
[0068]
In this case, the return of the incompressible fluid FHI to the working chamber 50 of the liquid-gas accumulator is ensured by the solenoid valve EVA, not by the check valve 56. This is the reopening of the drive solenoid valve EVA after a delay time during which the control unit can command during the third stroke. The hydraulic fluid is circulated by reopening the solenoid valve EVA instead of being circulated by the check valve 56 as in the specific embodiment of the present invention. Therefore, this delay time corresponds to the time during which the valve 12 remains in the open position.
[0069]
Thus, the present invention allows for the realization of barometric pressure control of a valve 12 of a mass-produced thermal engine, i.e., a high speed engine, which is reliable, inexpensive and has low engine energy demands.

Claims (10)

An apparatus (10) for operating a valve (12) of a heat engine of a motor vehicle,
Each said valve (12) has a shaft or handle (16),
The handle (16) is coupled to a drive (20) controlled by a control unit to cause the attached valve (12) to separate from and return to the valve seat;
Each said drive (20) is made in the form of a jack having a cylinder (22),
Inside the cylinder (22), the handle (16) of the attached valve (12) is slidable in the axial direction in a sealed state,
A movable piston (24) connected to a free end of the handle (16) of the valve is disposed in the interior of the cylinder (22).
The piston (24) is opposed to the upper hydraulic chamber (28) and the lower hydraulic chamber (30), each of which is supplied with an incompressible fluid (FHI) in the cylinder (22). Defining two hydraulic chambers (28, 30)
In each of the hydraulic chambers, the pressure (P ₂₈ , P ₃₀ ) of the fluid (FHI) is set alternately,
The pressure (P ₂₈ , P ₃₀ ) is such that the pressure dominating in one of the hydraulic chambers (28, 30) is different from the pressure in the other to activate the jack (20) and the valve (12) alternately. Is controlled by the control unit so that the pressure prevailing in the hydraulic chamber is alternately high or low.
In a device (10) for the operation of a valve (12) of a heat engine of a motor vehicle,
Each of the hydraulic chambers (28, 30) of the jack (20) can be connected to at least one independent liquid pressure source (32, 34) called an actuation source;
The liquid pressure source (32, 34) is connected to only one of the hydraulic chambers (28, 30);
The liquid pressure source (32, 34) provides for the movement of the valve (12) in a predetermined orientation, the movement of the valve (12) after the opposite direction to the predetermined direction, due to the movement of the valve (12). (12) means for elastically returning the fluid (FHI) for recovering the kinetic energy of (12),
Device (10) for the operation of a valve (12) of a heat engine of a motor vehicle. Apparatus according to claim 1, wherein said resilient return means is pneumatic. At least one of the hydraulic chambers (28, 30) can be connected to an additional source (36), referred to as a drain source, at which the hydraulic pressure of the fluid (FHI) is increased. Device (10) according to claim 1 or 2, characterized in that the pressure is reduced. The control unit includes a drive unit provided between one of the hydraulic chambers (28, 30) and the operating source (32, 34) coupled to one of the hydraulic chambers (28, 30). By alternately controlling the electromagnetic valve (EVA) of the above and a discharge electromagnetic valve (EVD) provided between one of the hydraulic chambers (28, 30) and the discharge source (36), characterized in that it is possible to adjust the pressure _{(P 28, P 30)} that govern in the fluid pressure chamber (28, 30) of the jack (20), any one of claims 1 to 3 An apparatus (10) according to one. Each of the actuation sources (32, 34) is composed of a liquid-gas accumulator (32, 34), and the liquid-gas accumulator (32, 34) has a coating (38, 40), and the coating (38, 40). In (40), the membrane (42, 44) separates the recovery chamber (46, 48) from the working chamber (50, 52), and the recovery chamber (46, 48) is separated and compressed gas ( GC), the working chambers (50, 52) being connected to the corresponding upper hydraulic chamber (28) or lower hydraulic chamber (30) of the installed jack (20). Device (10) according to any of the preceding claims, characterized in that the device (10) is filled with the incompressible fluid (FHI). The hydraulic chamber (28) above the jack (20) includes a first liquid-gas accumulator (32), the discharge source (36), the driving solenoid valve (EVA), and the discharge And the hydraulic chamber (30) below the jack can be directly connected to a second liquid-gas accumulator (34). An apparatus (10) according to claim 4, characterized in that: The check valve (56) is provided between the hydraulic chamber (28) above the jack (20) and the first liquid-gas accumulator (32). An apparatus (10) according to claim 6. The device (5) according to claim 3 or 4, characterized in that the discharge source (36) has a storage tank (54) connected to the crankcase of the engine where the reduced pressure ( _Pr ) prevails. 10). Each of the working chambers (50, 52) of the liquid-gas accumulator ( ₃₂ , ₃₄ ) can be maintained at a set pressure (Pc32, Pc34) as long as the valve (12) is closed. Device (10) according to claim 5, characterized in that it is connected to a pressure maintenance device. In a first stroke called closing of the valve (12), the control unit commands the closing of the driving electromagnetic valve (EVA) and the opening of the discharging electromagnetic valve (EVD). 1 of the liquid - vapor accumulator (32) has a first set pressure by the pressure maintenance device is maintained _{(Pc 32),} the second liquid - vapor accumulator (34) and the second set pressure _{(Pc 34)} , The first set pressure (Pc ₃₂ ) is higher than the second set pressure (Pc ₃₄ ), and the second set pressure (Pc ₃₄ ) is reduced in the crankcase of the engine. Higher than the pressure (P _r )
Next, in a second stroke called separation of the valve (12) from the valve seat, the control unit closes the discharge electromagnetic valve (EVD) and closes the drive electromagnetic valve (EVA). Command the opening,
Next, in a third stroke called return of the valve (12) to the valve seat,
The control unit commands the closing of the driving electromagnetic valve (EVA),
Next, in a fourth stroke in which the valve (12) is completely closed, the control unit determines that the opening of the discharge electromagnetic valve (EVD) is continued until the first stroke in which the valve (12) is closed. Command,
The method of controlling an actuator (10) of a valve (12) of a heat engine of a motor vehicle according to claim 7, characterized in that it is combined with claim 8 or 9.